1. Field of the Invention
The present invention relates to a traveling transmission apparatus for a work vehicle, including a stepless change-speed unit receiving power from an engine, a gear transmission mechanism receiving power from the stepless change-speed unit, and a rear-wheel differential mechanism for transmitting power from the gear transmission mechanism to rear wheels, the change-speed unit, the gear transmission mechanism and the differential mechanism all being disposed rearwardly of the engine.
2. Description of the Related Art
The traveling transmission apparatus of the above-noted type is known form e.g. the Japanese Patent Application “Kokai”, No.: Hei. 11-91379 (see paragraphs [0054]-[0056] and FIGS. 1–3). In this traveling transmission apparatus, a change-speed case of the stepless change-speed unit is coupled via a main clutch housing to a flywheel housing portion disposed rearwardly of the engine and to the rear of this change-speed case, there is connected a traveling transmission case housing therein the gear transmission mechanism and the rear-wheel differential mechanism.
When the above-described conventional traveling transmission apparatus is mounted on a work vehicle, for effecting e.g. a maintenance operation of a hydraulic circuit of the stepless change-speed unit, this operation was difficult because of the poor accessibility to the stepless change-speed unit from the outside of the vehicle body. Further, regarding a desire to dispose the engine and the traveling transmission unit in a compact manner in the vicinity of the rear axle, the above construction cannot fully meet the desire because of a significant distance separating between the engine and the rear-wheel differential mechanism.